Enhancement of speech degraded by background noise has been a topic of interest in the past decades due to its wide range of applications. Some of the important applications are in digital hearing aids, hands free mobile communications and in speech recognition devices. The objectives of a speech enhancement system are to improve the quality and intelligibility of the degraded speech. Speech enhancement algorithms that have been developed can be mainly categorised into spectral subtraction methods, statistical model based methods and subspace based methods. Conventional single channel speech enhancement algorithms have been found to improve the speech quality, but have not been successful in improving the speech intelligibility in presence of non-stationary background noise. Babble noise, which is commonly encountered among hearing aid users, is considered to be highly non-stationary noise. Thus, an improvement in speech intelligibility in such scenarios is highly desirable.